Railway traffic controlling apparatus



Jan. 7, 1958 J. M. PELIKAN RAILWAY TRAFFIC CONTROLLING APPARATUS 3Sheets-Sheet 1 Filed Oct. 15, 1952 INVENTOR. JOIIIZ M pell'li'all BY w.L. W.

HIS ATTORNEY Jan. 7, 1958 A J. M. PELIKAN RAILWAY TRAFFIC CONTROLLINGAPPARATUS Filed Oct. 15, 1952 3 Sheets-Sheet 2 Y mm m N L m d m m P T MT n n a A m m w A w .L m J Y H, gm 1 m B 1 rw hw m mv a G n. Em m aw #w4 A mu wwl 5% wwhm w kw #lJ n m AWN m u u m mafq w l w w m QM r fi mm mARN RH L.

J. M. PELIKAN 2,819,388

RAILWAY TRAFFIC CONTROLLING APPARATUS 3 Sheets-Sheet 3 I' I l I I I i lI I I I I l i l l I I I I l I E I I l I I i l g l I I J Jan. 7, 1958Filed Oct. 15, 1952 A mm kw Wm h m REQMN SQMN INVENTOR. John M Pelikanw. k squib.

1 1s ATTORNEY aw saw M rxm EIG \sw AE 3% A @EQ United States atent ()12,819,388 Patented Jan. 7, 1958 RAILWAY TRAFFIC CONTROLLING APPARATUSJohn M. Pelikan, Brooklyn, N. Y., assignor to Westinghouse Air BrakeCompany, Wilmer-ding, Pin, :1 corporation of Pennsylvania ApplicationOctober 15, 1952, Serial No. 314,843

14 Claims. (Cl. 246-3) My invention relates to railway trafficcontrolling apparatus. More particularly, my invention relates toapparatus of the type which is known as traflic locking apparatus, bymeans of which trafiic governing devices, such for example as signalsfor any given stretch of railway track, are in part manuallycontrollable for governing trafiic movements in both directions, and bymeans of which such traffic governing devices, after being con trolledfor governing traffic movements in one direction over a stretch ofrailway track, cannot be controlled for governing trafiic movements inthe opposite direction while the stretch of track is occupied by atrain, or while one traflic governing device remains controlled forauthorizing a train to proceed in the former direction into the stretchof track.

One form of traffic locking apparatus which has been used requires jointaction by persons at two different control stations for manuallycontrolling trafiic movements in both directions over a stretch ofrailway track. Each of the two control stations may be provided with aninterlocking machine, and each of the interlocking machines may beequipped with a traffic lever which is mechanically interlocked with asignal lever which controls a signal for governing trafiic movementsinto the stretch of railway track at the corresponding end.

In the particular form of apparatus shown embodying my invention,however, a trafiic control circuit arrangement manually controllablefrom only one control station is employed, in which polar control relaysare energized in series by current of one polarity or the other in acircuit which includes a contact of each of a plurality of track relaysand other tratfic controlled relays for a corresponding stretch ofrailway track and which also includes contacts of two time locking stickrelays, one for each end of the stretch of track, controlled inconjunction with a signal for governing traflic movements entering thestretch of track at the corresponding end. Each of the polar controlrelays is of the polar stick type having polar contacts which, when thecorresponding relay becomes deenergized, remain closed in the normal orthe reverse position to which they were last operated in response tocurrent of normal or reverse polarity, respectively.

Two track circuits, of the coded type, one for each direction of trallicmovements, are provided for each track section between signals, adjacentopposite ends of the stretch of track, which govern traffic movementscut of the stretch of track. The track circuits for a given direction oftramc movement are set up by contacts of the polar control relays whenclosed in a given or normal position in response to energization of thepolar control relays by current of a given normal polarity, and thetrack circuits for the opposite direction of traffic movement are set upby contacts of the polar control relays when closed in the opposite orreverse position in response to energization of the polar control relaysby current of the opposite or reverse polarity.

It has been found that, with such a track circuit scheme, and withcontacts of the track relays or of relays controlled by the track relaysincluded in the tratiic control circuit arrangement, a locked-outcondition of the traflic control circuit can occur under someconditions. If, for example, the contacts of one or more of the polarcontrol relays should become misplaced, such as by an induced surge offoreign current while the trafiic control circuit is open due tooccupancy of the stretch of track by a train, both track circuits forone or more of the track sections are deprived of energized current. Itis then necessary for a signal maintainer or other authorized employeeto manually efiect restoration of the misplaced polar contacts of thepolar control relays to a position in agreement with the polar contactsof the other polar control relays.

Since the traffic control circuit is carried from one signal location toanother by line wires on a pole lineparalleling the stretch of track,this circuit is extremely vulnerable to induced transient voltages whichresult in the surges of foreign current previously mentioned. Thesetransient voltages are induced in the line wires by ligntning or otherstatic charges, by unusual transient voltage conditions in an electricpower line usually carried on the same poles, or by accidental,momentary crosses between the traflic control circuit and other circuitsof the same pole line. Because of the nature of these induced transientvoltages, the current surges occur in portions of the trafiic circuitwhich are separated by open relay contacts from the rest of the circuit,that is, when the control circuit is open at one or more places by relaycontacts released due to a train occupying the stretch of track or dueto an entering signal having been cleared. The polar control relays,being very quick acting, are extremely susceptible to operation by thesecurrent surges, even though of very short duration, when the relaywindings are otherwise deenerg'ized.

An object of my invention, therefore, is the provision of means forprotecting against misplacement of the polar contacts of polar controlrelays connected in series with each other in a control circuit scheme,the misplacement being due to an induced surge of foreign current whilethe control circuit is open as, for example, in a series railway trafiiccontrol circuit arrangement.

Although, as shown in the accompanying drawings, three polar controlrelays are energized in series with each other and in series withcontacts of a plurality of track relays and other relays, my inventionis not limited to this particular form and arrangement of apparatus. Myinvention can also be applied to control circuits, for other electricaldevices, including various other numbers of polar control relays, oreven to a control circuit ineluding only one such relay. It is notnecessary that a control circuit embodying my invention shall includecontacts of track relays or of other relays in series with one or morepolar control relays, or that the control circuit shall be normallyenergized.

My invention can, for example, be applied to a control circuit whichincludes only one polar control relay and means for energizing it bycurrent of normal and reverse polarities. My invention can also beapplied to a traffic control arrangement such as shown in Letters Patentof the United States No. 2,271,510, granted February 3, 1942, to Earl M.Allen for Railway T raflic Controlling Apparatus, in which a trafficcontrol circuit includes four polarized traffic control relays 3FR, SFR,7FR and 9FR connected in series in a control circuit which is normallydeenergized. As is obvious, if my invention were applied to a normallydeenergized circuit arrangement including one or more polar controlrelays as shown in the Allen Pattent No. 2,271,510, it would protectagainst misplacement of the polar contacts of one or more of the polarcontrol relays, such as by an induced surge of foreign current, whilethe traflic control circuit is in its normally deenergized condition.

Another object of my inventionds therefore the provision of means forprotecting against misplacement, due to an induced surge of foreigncurrent, of the polar contacts of one or more polar control relaysconnected in a control circuit which includes one or more polar controlrelays and which is normally deenergized, or which becomes deenergizedaccidentally, as by a broken connection.

A feature of my invention for accomplishing these objects is theprovision of a neutral line relay for each polar control relay,connected in series with the cor responding polar control relay; and aback contact of each of these neutral line relays included in a pathconnected in shunting relation around the control winding of thecorresponding polar control relay in a control circuit which includesthe corresponding polar control relay.

I shall describe one form of apparatus embodying my invention, and shallthen point out the novel features thereof in claims.

The accompanying drawings, Figs. 1a, 1b, and 10, when placed end to endin the order named, with Fig. 1a on the left, constitute a diagrammaticview showing one form of apparatus embodying my invention for a stretchof railway track which is provided with a plurality of signals spacedconsecutively along the stretch of track for governing traffic movementsover the stretch of railway track. This apparatus embodies a pluralityof polar control relays, one for each of several signal locations,connected in series, each of the polar control relays having one or morecontacts which, when the corresponding relay becomes deenergized, remainclosed in the normal or the reverse position to which they were lastpreviously operated in response to current of normal or of reversepolarity, respectively. The apparatus also embodies a plurality ofneutral line relays, one for each polar control relay, connected inseries with the polar control relays, with a back contact of each of theneutral line relays being included in a path connected in shuntingrelation around the control Winding of the corresponding polar controlrelay. Energization of the circuit including the polar control relaysand the neutral line relays connected in series, by current of normal orreverse polarity, is manually controllable from only one controlstation, with contacts of trafiic controlled relays being included inseries with the control windings of the polar control relays and theneutral line relays. Two track circuits of the coded type are providedfor each of the track sections, one for each direction of trafficmovement. The track circuits for a given direction of traific movementare set up by contacts of the polar control relays when closed in thegiven or normal position, and the track circuits for the oppositedirection of traffic movement are set up by contacts of the polarcontrol relays when closed in the opposite or reverse position.

Similar reference characters refer to similar parts in the drawings.

A stretch of railway track is illustrated, over which traflic movementsare normally made from left to right, as shown in the drawings, which Ishall assume is the eastbound direction, but over which trafiicmovements may also at times be made in the opposite or westbounddirection. In order to simplify the drawings, the track, comprising twoparallel series of track rails, is represented by a single line.

The stretch of track is divided by insulated joints 6 into sections,designated by the reference characters 1T, AT, BT and ST. Each of thetrack section IT and ST is provided with a track circuit including asuitable source of current such as a battery 7, connected across therails adjacent one end of the section, and a track relay, designated bythe reference character 1TR or STR, respectively, connected across therails adjacent the oposite end of the section.

A suitable source of alternating current is provided such, for example,as an alternator, designated by the reference character L, shown in Fig.lb, having terminals BX and NX.

Each of the track sections AT and ET is provided with a first trackcircuit which is at times supplied with coded alternating currentadjacent the east end of the corresponding section for controllingeastbound traffic governing means, and is provided with a second trackcircuit which is at times supplied with coded alternating currentadjacent the west end of the corresponding section for controllingwestbound traific governing means. Each of the track circuits forsection AT includes the winding d of a track transformer, designated bythe reference character 3LT, connected across the rails adjacent theeast end of the section, and the winding d of a track transformer,designated by the reference character ZRT, connected across the railsadjacent the west end of the section.

For controlling eastbound traflic governing means, the eastbound trackcircuit for section AT is energized by coded alternating currentsupplied to winding m of transformer 3LT from terminals BX and NX overfront contacts of an eastbound tratlic control relay, designated by thereference character 3EFP. A code following direct current track relay,which may be of the biased neutral type operable by only current of thepolarity indicated by the arrow in the symbol for the relay, for theeastbound track circuit for section AT, designated by the referencecharacter ZRTR, is energized by current received from winding m oftransformer 2RT over back contacts of a westbound traific control relay,designated by the reference character ZWFP, through a rectifier,designated by the reference character 2R1.

For controlling westbound traflic governing means the westbound trackcircuit for section AT is energized by alternating current supplied towinding m of transformer 2RT from terminals BX and NX over frontcontacts of the westbound trafiic control relay ZWFP.

Each of the track circuits for section BT includes the winding d of atrack transformer, designated by the reference character 4LT, connectedacross the rails adjacent the east end of the section, and the windinga. of a track transformer, designated by the reference character 3RT,connected across the rails adjacent the west end of the section. Thetrack circuits for section BT are energized similarly to the trackcircuits for section AT, as already described, for controlling trackrelays, designated by the reference characters 3RTR and 4LTR, forcontrolling eastbound and westbound traffic governing means,respectively.

The rectifiers 2R1, 3R1, 3L1 and 4LI may be of any suitable design such,for example, as the well-known bridge type comprising four asymmetricunits, designated by the reference characters i1, i2, i3, and i4, whichmay be of the well-known copper oxide half-wave rectifier type.

Signals designated by the reference characters RA2 and L2 are locatedadjacent the opposite ends of track section IT, and signals designatedby the reference characters R4 and LA4 are located adjacent the oppositeends of track section ST. A signal designated by the reference characterR3 is located adjacent the adjoining ends of sections AT and BT. SignalsRA2, R3 and R4 govern eastbound traffic movements, and signals L2 andLA4 govern westbound traflic movements. The signals may be of anysuitable design such, for example, as the wellknown color light type,each of which has green, yellow and red light units, designated by thereference characters G, Y and R, respectively, as shown in the drawings.

Track switches such as those designated by the reference characters 1and 5 may be located in track sections IT and ST, respectively.

Operation of signals RA2, L2, R-tand LA-t and switches 1 and 5 may becontrolled manually, at least in part, by

asrasss manually operable devices such, for example, as interlockingmachine levers, designated by the reference characters 2V and 4V, forcontrolling the signals. Each of the levers 2V and 4V has a normalposition designated by the reference character 11, in which it is shownin the drawings, a first or eastward position designated by thereference character r to the right, as shown in the drawings, and asecond or westward position designated by the reference character f tothe left, as shown in the drawings.

A traffic lever, designated by the reference character FV, is alsoprovided adjacent lever 2V, as shown in Fig. la. Lever FV has a normalposition n, in which it is shown, and a reverse position r to the right,as shown in the drawing. 7 Contacts operatedby levers 2V, 4V and FV arerepresented by circles, each of which is placed a reference character toshow the position of the corresponding lever in which the contact isclosed. Contact 77 of lever 2V, for example, shown in the upperleft-hand corner of Fig. la, is represented by a circle in which thereference character 2' is enclosed to show that contact 77 is closedwhile lever 2V is in its r position only. As another example, contact 16of lever 2V, shown just below contact 77, is represented by a circle inwhich the reference character n is enclosed to show that contact 16 isclosed while lever 2V is in either its n or its 1' position or at anypoint between those two positions.

Time locking stick relays, designated by the reference characters ZASand 4A5, are controlled in part by levers 2V and 4V, respectively, inconjunction with the control of signals by these levers.

Time element devices, shown as time element relays designated by thereference characters 2TE and 4TB, are associated with the control ofrelays 2A8 and 4A8, respectively, by levers 2V and 4V, respectively.Each of the time element relays 2TE and 4TE is of a type having contactswhich become closed only upon the lapse of a measured period of timeafter the corresponding relay becomes energized.

A signal lighting relay, designated by the reference character RAZER, iscontrolled in part by lever 2V for controlling signal RA2. Signallighting relays, designated by the reference characters LA4ER and 4RER,are controlled in part by lever 4V for controlling signals LA4 and R4,respectively. A relay similar to relay 4RER would normally be providedfor signal L2. However, since these control circuits are not part of myinvention and are not necessary for an explanation of the apparatusshown, the control relay and circuits for signal L2 have been omitted.

Polar control relays are provided, one for each of given signallocations. Each of the polar control relays is designated by thereference character FR preceded by a numeral which is the same as thatin the reference character for the corresponding signal.

Neutral line relays are also provided, one for each polar control relay.Each of the neutral line relays is designated by the reference characterBPR preceded by a numeral which is the same as that in the referencecharacter for the corresponding polar control relay.

The polar control relays and the neutral line relays are all connectedin series in a trafiic control circuit arrangement which includes frontcontacts of track relays ITR and STR and front contacts of time lockingstick relays 2A8 and 4A8, and at times includes front contacts of homesignal relays, designated by the reference character HR preceded by adistinguishing prefix, and front contacts of traffic control relays,each of which is designated by the reference character FP preceded by adistinguishing prefix.

The polar control relays and neutral line relays in the traffic controlcircuit arrangement are energized by current of normal or reversepolarity controlled by a master polar relay, designated by the referencecharacter FSR, which is in turn controlled by pole-changing contacts oftraflic lever FV. Under some conditions, themaster polar relay FSR couldbe omitted, and energization of the polar control relays and neutralline relays by current of normal or reverse polarity could then becontrolled directly by pole-changing contacts of trafiic lever FV.

Each of the polar control relays FR, when energized by current of normalor reverse polarity, controls an eastbound or a westbound trafficcontrol relay, respectively, designated by the reference characters EFPand WFP, respectively, preceded by a distinguishing numeral.

Code transmitting devices, each designated by the reference characterCT, preceded by the reference character 75 or 180, may be of a typehaving a contact which, while the corresponding code transmitting deviceCT is energized, will open and close at a frequency of 75 or times perminute, respectively. Each of the code transmitting devices CT isconnected directly across the terminals of a suitable source of current,and therefore its contact is being repeatedly opened and closed at thefrequency of 75- or 180 times per minute, as designated by the referencecharacter of the corresponding device CT.

A decoding transformer, designated by the reference character 2T, has aprimary winding m which is energized by pulses of current of alternatelyone polarity or the other controlled by relay ZRTR.

A home signal relay, designated by the reference character ZRHR, forsignal RAZ, is energized by current of either the 75 or the 180 codefrequency supplied from secondary winding d of transformer 2T through arectifying contact 57 of relay ZRTR. A distant signal relay, designatedby the reference character 2RDR, for signal RA2, is energized through adecoding unit, designated by the reference character 180DU, which is ofa well-known type passing only current of the 180 code frequency. RelayZRDR will therefore be operated only while winding in of transformer 2Tis being energized by current of the 180 code frequency.

Decoding transformers, designated by the reference characters 3T and 4Tfor signals R3 and LA4, respectively, are energized similarly totransformer 2T as just described.

Home and distant signal relays, designated by the reference charactersSRI-IR and 3RDR, respectively, for signal R3 are operated similarly toZRHR and ZRDR, respectively. Home and distant signal relays, designatedby the reference characters 4LHR and 4LDR, respectively, for signal LA4are also operated similarly to relays ZRHR and ZRDR, as alreadydescribed. A home signal relay, designated by the reference characterSLHR, is energized in response to operation of relay 3LTR by codedcurrent. Each of the relays ZRHR, SRHR and 4LHR is of a type which isslow to pick up and slow to release. Relay SLHR is made slow to releaseby an asymmetric unit, designated by the reference character i5,connected in multiple with its control winding.

A suitable source of current such, for example, as a battery, designatedby the reference character 2Q, having terminals designated by thereference characters 2B and 2N, is provided adjacent the west end of thestretch of track, and a suitable source of current such, for example, asa battery, designated by the reference character 4Q, having terminalsdesignated by the reference characters 4B and 4N, is provided adjacentthe east end of the stretch of track. A third suitable source of currentsuch, for example, as a battery, designated by the reference character3Q, having terminals designated by the ref- ;rgnce characters 38 and 3N,is provided adjacent signal Having described, in general, thearrangement and control of the various parts of one form of apparatusembodying my invention, I shall now describe the circuits and operationin detail.

As shown in the drawings, each of the track sections 1T, AT, BT and STis unoccupied; relays lTR and STR are energized; each of the levers 2Vand 4V is in the normal or n position, and therefore each of the signalsRA2, L2, R4 and LA4 is displaying the red or stop indication; signal R3is displaying the yellow or caution proceed indication; relays 2A8 and4AS are energized; relays 2TB and 4TE are deenergized; traflic controllever FV is in its 11 position, and therefore relay FSR is energized bycurrent of normal polarity. With relay FSR energized by current ofnormal polarity, its pole-changing contacts 62 and 76 are closed in thenormal position for energizing the polar control relays ZFR, 31 R and 41R, and the neutral line relays ZBPR, 3BPR and dBPR, by current of normalpolarity. Relays ZEFP, EEFP, 4EFP, ZRHR, 3RHR, and ZRDR are thereforealso energized, while track relays ZRTR and 3RTR are periodicallyenergized by coded track current. Each of the code transmitting devices75CT and ISOCT is constantly energized, and is therefore repeatedlyclosing and opening its contacts alternately at a frequency of 75 or 180times per minute, respectively. Relays ZWFP, RAZER, 3WFP, SLTR, 3LHR,SRDR, LA4ER, 4RER, 4LDR, 4LHR, 4LTR, and 4WFP are deenergized.

In Fig. 1a, code transmitting device 75CT is connected directly acrossterminals 28 and 2N, and is therefore repeatedly closing and opening itscontact 87 at a frequency of 75 times per minute. In Fig. 1/), codetransmitting devices '75CT and 180CT are connected directly acrossterminals 38 and 3N, and are therefore repeatedly closing and openingtheir contacts at a frequency of 75 and 180 times, respectively, perminute. In Fig. lc, code transmitting devices 75CT and ISOCT areconnected directly across terminals 4B and 4N, and are thereforerepeatedly closing and opening their contacts at a frequency of 75 and180 times, respectively, per minute.

In Fig. la, red lamp R of signal HA2 is shown lighted by a circuitpassing from terminal 2B, through the back point of contact 8 of relayRAZER, and lamp R of signal RA2 to terminal 2N. The red lamps of signalsL2, R4 and LA4 are also lighted by circuits which are similar to thecircuit just traced for signal RAZ.

In Fig lb. yellow lamp Y of signal R3 is shown lighted by a circuitpassing from terminal 313, through the front point of contact 13 ofrelay 3EFP, front point of contact 14 of relay SKI-IR, the back point ofcontact 15 of relay 3RDR, and lamp Y of signal R3 to terminal 3N.

As shown in Fig. 1a, relay 2AS is energized by a stick circuit passingfrom terminal 28, through contact 16 of lever 2V, contact 17 of relayRAZER, front point of contact 18 of relay 2A8, and the winding of relay2AS to terminal 2N. Relay 4AS, shown in Fig. 1c, is also energized by asimilar stick circuit.

Relay FSR is energized by current of normal polarity passing fromterminal 218, through contact 26 of lever FV, winding of relay FSR, andcontact 27 of lever FV to terminal 2N. Relays ZBPR, ZFR, 3BPR, 3FR, 4BPRand 4FR are therefore energized by current of normal polarity in acircuit which will be traced later. The polar contacts of each of therelays ZFR, 3FR and 4FR are therefore closed in the normal position.

With contact 30 of relay 4FR closed in the normal position, relay 4EFPis energized by both a pickup and a stick circuit, the pickup circuitpassing from terminal 43, through contact 30 of relay 4FR closed in thenormal position, contacts 31 and 32 of relays 4A8 and STR, respectively,contact 34 of relay lWFP, and the winding of relay 4EFP to terminal 4N.The stick circuit for relay 4EFP is the same as the pickup circuit justtraced except that it includes contact 33 of relay 4EFP instead ofcontacts 31 and 32 of relays 4A8 and STR.

With relay 4EFP thus energized while relay 4RER is deenergized, windingm of track transformer 4LT is energized by current of 5 code frequencypassing from terminal BX, through contact 35 of code transmitting device75CT, back point of contact 37 of relay 4RER, front point of contact 38of relay 4EFP, winding m of transformer 4LT, and the front point ofcontact 39 of relay 4EFP to terminal NX. Alternating current, coded atthe frequency of 75 times per minute, is therefore supplied by winding dof transformer 4LT over the rails of section BT to winding (1 oftransformer 3RT.

With transformer 3RT thus energized, relay 3RTR is energized by circuitmeans including Winding m of transformer 3RT, back point of contact 41of relay SWFP, rectifier 3R1, winding of relay 3RTR, and the back pointof contact 40 of relay SWFP. With relay 3RTR thus energized by currentcoded at the frequency of 75 times per minute, primary Winding m oftransformer 3T is being repeatedly energized by current pulses of normaland reverse polarity alternately. The circuit by which the pulses ofnormal polarity are supplied to winding m of transformer 3T passes fromterminal 3B, through the front point of contact 42 of relay SRTR, andthe middle portion of winding m of transformer 3T to terminal 3N. Thecircuit by which the pulses of reverse polarity are supplied to windingm of transformer 3T passes from terminal 3B, through the back point ofcontact 42 of relay 3RTR, and the lowest portion of winding m oftransformer 3T, as shown in the drawing, to terminal 3N.

Relay 3RHR is therefore energized by current passing from winding d oftransformer 3T through a rectifying contact 43 of relay 3RTR. Withwinding m of transformer 3T energized by pulses of current of normal andreverse polarities at the frequency of 75 times per minute, relay 3RDRwill not be energized, since current of this frequency cannot passthrough the corresponding decoding unit 180DU. With relays SEFP and 3RHRenergized and relay SRDR deenergized, lamp Y of signal R3 is lighted bythe circuit previously traced.

With contact 44 of relay 31 R closed in the normal position, and withrelay 3RHR energized, both a pickup and a stick circuit are closed forenergizing relay SEFP. The pickup circuit for relay 3EPP passes fromterminal 3B, through contact 44 of relay 3FR closed in the normalposition, contact 45 of relay 3RHR, contact 47 of relay 3WFP, and thewinding of relay SEFP to terminal 3N. The stick circuit for relay 3EFPis the same as the pickup circuit just traced except that it includescontact 46 of relay 3EFP instead of contact 45 of relay BRHR.

With relays ZiRHR and 3EFP energized, winding m of transformer 3LT isenergized by alternating current coded at the frequency of 180 times perminute in a circuit passing from terminal BX, through the front point ofcontact 48 of relay 3EFP, winding m of transformer 3LT, front point ofcontact 49 of relay 3EFP, contact 50 of code transmitting device 180CT,and the front point of contact 53 of relay SRHR to terminal NX.Alternating current, coded at the frequency of 180 times er minute, istherefore supplied from winding d of transformer 3LT over the rails ofsection AT to winding d of transformer ZRT.

Relay ZRTR is therefore energized by a circuit including winding :11 oftransformer ZRT, the back point of contact 55 of relay ZWFP, rectifier2R1, winding of relay ZRTR, and the back point of contact 54 of relayZWFP. With relay 2RTR thus energized by current coded at the frequencyof 180 times per minute, winding m of transformer 2T is energized bycurrent of normal and reverse polarity alternately at the frequency of180 times per minute. Both relays ZRHR and ZRDR are therefore energized.

Both a pickup and a stick circuit are closed for relay ZEFP, the pickupcircuit passing from terminal 2B, through contact 58 of relay ZFR closedin the normal position, contact 59 of relay ZRHR, contact 61 of relayZWFP, and the winding the relay ZEFP to terminal 2N. The stick circuitfor relay ZEFP is the same as the pickup circuit just traced except thatit includes contact 60 of relay ZEFP instead of contact 59 of relayZRHR.

Each of the relays EFP and WFP is of the slow release type.

With the track relays, time locking stick relays, home signal relaysZRHR and 3RHR, and relay 4EFP energized, while relay FSR is energized bycurrent of normal polarity, the polar control relays PR and the neutralline relays BPR are energized by current of normal polarity passing fromterminal 2B, through contact 62 of relay FSR closed in the normalposition, contacts 63 and 64 of relays 1TR and 2A8, respectively,windings of relays 2BPR and 21 R, contact 66 of relay 2RHR, a line wireto signal location R3, contact 68 of relay 3RHR, windings of relays 3BPRand 3FR, another line wire to the east end, contact 71 of relay 4EFP,windings of relays 4BPR and 4FR, contacts 74 and 75 of relays 4A5 andSTR, respectively, a return line wire to the west end, and contact 76 ofrelay FSR closed in the normal position, to terminal 2N.

I shall assume that a leverman moves lever 2V to the rposition in orderto clear signal RA2 for an eastbound train. With lever 2V in the rposition, relay RA2ER will become energized by a circuit passing fromterminal 2B, through contact 77 of lever 2V, contacts 78 and 79 ofrelays 1TR and 2FR, respectively, contact 80 of relay 2RHR, and thewinding of relay RAZER to terminal 2N. With relay RA2ER energized,contact 8 of this relay will become open, at its back point, therebyextinguishing lamp R of signal RA2, and will become closed at its frontpoint, thereby completing a circuit for lighting green lamp G of signalRA2, this circuit passing from terminal 2B, through the front point ofcontact 8 of relay RAZER, front point of contact 9 of relay 2RDR, andlamp G of signal RA2 to terminal 2N.

When the leverman moves lever 2V away from its n position toward the rposition, contact 16 of lever 2V will become opened, therebydeenergizing relay 2AS. Upon deenergization of relay 2AS, contact 64 ofthis relay will open the circuit previously traced for the BPR and FRrelays.

I shall assume further that, before the eastbound train passes signalRA2, the leverman decides to stop the train at this signal. He willtherefore return lever 2V to its n position, thereby deenergizing relayRAZER and thus causing green lamp G of signal RAZ to become extinguished and lamp R of this signal to again be lighted. With lever 2Vagain in its 11 position and relay RA2ER deenergized, an energizingcircuit will be completed for time element relay 2TB, this circuitpassing from terminal 23, through contact 16 of lever 2V, contact 17 ofrelay RAZER, back point of contact 18 of relay 2A8, and relay 2TB toterminal 2N.

Upon the lapse of a measured period of time, relay 2TE will close itsfront contact 19, thereby completing a pickup circuit for relay 2AS,this circuit passing from terminal 2B, 'through contact 16 of lever 2V,contact 17 of relay RAZER, contact 19 of relay 2TB, and the winding ofrelay 2A8 to terminal 2N. Relay 2A8, upon becoming energized by itspickup circuit, will again complete its stick circuit previously traced,and will also again complete, at its contact 64, the circuit previouslytraced for the BPR and FR relays.

I shall assume that the leverman later decides to again clear signal RA2for the eastbound train. He will there fore again move lever 2V to its rposition, causing relay RAZER to again be energized, which in turncauses lamp R of signal RA2 to be extinguished and lamp G of this signalto be lighted, as previously described. Relay 2AS will new again bedeenergized, causing the polar control relays PR and the neutral linerelays BPR to again be deenergized.

When the eastbound train enters section 1T, deenergizing relay 1TR,contact 78 of this relay will open the circuit previously traced forrelay RAZER, causing relay RAZER to become deenergized. Lamp G of signalRA2 will therefore be extinguished and lamp R will again be lighted.When relay 1TR becomes deenergized,

10 its contact 63 opens the circuit for the BPR and FR relays at anotherpoint.

If, now, while the train is in section 1T, the leverman returns lever 2Vto its 11 position, relay 2A8 will become energized by a second pickupcircuit, this circuit passing from terminal 28, through contact 1.6 oflever 2V, contact 17 of relay RA2ER, contact 20 of relay 1TR, and thewinding of relay ZAS to terminal 2N. With relay 2AS again energized, itscontact 64 will be closed in the circuit for the BPR and FR relays, butthis circuit will still be open at contact 63 of relay 1TR.

If it is decided to permit the eastbound train to continue its movementpast signal R4 at the opposite end of the stretch, a leverman will movelever 4V to its r position, thereby completing a circuit for energizingrelay 4RER, this circuit passing from terminal 4B, through contact 81 oflever 4V, various contacts governed by trafiic conditions in advance,not shown but indicated by the dotted line, contact 82 of relay STR, andthe winding of relay 4RER to terminal 4N. With relay 4RER thusenergized, its contact 12 will open the circuit for the red lamp R ofsignal R4, and, at its front point, will complete a circuit for lightingeither lamp Y or lamp G of this signal, according to traffic conditionsin advance, as indicated by the dotted portion of the circuitscontrolled by the front point of contact 12 of relay 4RER.

With relay 4RER energized, alternating current, coded at the frequencyof 180 times per minute will be supplied to winding m of transformer 4LTover a circuit passing from terminal BX, through contact 36 of codetransmitting device 1536GT, front point of contact 37 of relay 4RER,front point of contact 38 of relay 4EFP, winding m of transformer 4LT,and the front point of contact 39 of relay 4EFP to terminal NX. Windingd of transformer 4LT will therefore supply alternating current, coded atthe frequency of 180 times per minute, to the rails of section ET, forenergizing winding d of transformer 3RT.

Relay SRTR will therefore now be energized by current coded at thefrequency of 180 times per minute, so that winding m of transformer 3Twill now be energized by current of normal and reverse polarityalternately at the frequency of 180 times per minute. Relay SRHR willremain energized as before, and, in addition, relay SRDR will beenergized by current of the 180 code frequency passing through thedecoding unit 180DU. When relay 3RDR becomes energized, its contact 15will open at its back point, thereby extinguishing lamp Y of signal R3,and will become closed .at its front point, thereby completing a circuitfor lighting lamp G of signal R3, this circuit passing from terminal313, through the front point of contact 13 of relay 3EFP, front point ofcontact 14 of relay 3RHR, front point of contact 15 of relay 3RDR, andlamp G of signal R3 to terminal 3N.

The eastbound train, upon entering section AT, will deenergize winding dof transformer 2R1, which in turn will cause relay ZRTR to becomedeenergized, and then transformer 2T and relays ZRDR and ZRHR will alsobecome deenergized. Relay ZRHR, upon becoming de energized, opens thepickup circuit for relay ZEFP, which, however, remains energized by itsstick circuit. When relay ZRHR becomes deenergized, its contact opensthe circuit for relay RAZER at another point, and its contact 66 alsoopens the circuit for relays BPR and FR another point.

With the circuit for relays BPR and FR open, and therefore deenergized,a shunt path is completed around the winding of each of the relays FRthrough the back points of the adjacent relays BPR. For example, withrelay ZBPR deenergized, a shunt path including contact 65 of relay 2BPRis completed around the winding of relay 2FR. With a shunt path thusprovided around the wind ing of each of the FR relays, if there shouldnow be an induced surge of foreign current of reverse polarity in thecircuit portion, which includes relays 3FR and 4FR,

11 and which is disconnected at contact 66 of relay ZRHR from thecircuit portion which includes relay ZFR, the induced current surgewould flow through the shunt paths and in that way bypass the controlwindings of the relays 3BR and 41 R. The induced current surge wouldtherefore not cause the polar contacts of relays 3FR and AFR to be movedto their reverse position.

When the train leaves section 1T, relay ITR will become energized,thereby opening its contact 20 in the second pickup circuit traced forrelay ZAS. Contact 78 of relay lTR will now again be closed in thecircuit for relay RA2ER, and contact 63 of relay lTR will again beclosed in the circuit. for the BPR and FR relays.

When the train enters section BT, winding d of transformer 3R1 willbecome deenergized, causing relay 3RTR to become deenergized, and inturn causing transformer ST and relays SRHR and 3RDR to also bedeenergized. The pickup circuit for relay 3EFP will now be open atcontact 45 of relay 3RHR, but relay 3E? will remain energized by itsstick circuit.

When relay SRHR becomes deenergized, its contact 68 Will open thecircuit for the BPR and FR relays at another point, and its contact 53will open, at its front point, the circuit previously traced forenergizing winding m of transformer 3LT by current coded at thefrcquency of 180 times per minute. A circuit will now be completed forenergizing Winding m of transformer 3LT by current ended at thefrequency of 75 times per min ate, this circuit passing from terminalBX, through the front point of contact 48 of relay SEFP, Winding m oftransformer 3LT, front point of contact 49 of relay SEEP, contact 51 ofcode transmitter 7SCT, back point of contact 52 of relay 3LHR, and theback point of contact 53 of relay SSRHR to terminal NX. When relay 3RHRbecomes deenergized, its contact 14 will open, at its front point, thecircuit previously traced for lamp G of signal R3, causint this lamp tobe extinguished, and will complete a circuit for lighting lamp R ofsignal R3, this circuit passing from terminal 3B, through the frontpoint of contact 13 of relay 3EFP, back point of contact 14 of relay3RHR, and lamp R of signal R3 to terminal 3N.

When the train leaves section AT, winding d of transformer 2RT willbecome energized by current coded at the frequency of 75 times perminute, causing relay ZRTR to in turn become energized by current codedat this frequency. Relay ZRHR will therefore again be energized, butrelay ZRDR will remain deenergized. With relay ZRHR again energized, thepickup circuit for relay ZEFP will again become closed at contact 59 ofrelay ZRHR. Also, with relay ZRHR again energized, its contact 66 willagain be closed in the circuit for relays BPR and PR, and contact 80 ofrelay ZRHR will again be closed in the circuit traced for relay RAZER.

If desired, the leverman can now control signal RAJ. to display a yellowor caution indication for a second eastbound train to pass signal RA2.He will accomplish this by again moving lever 2V to the r position,thereby causing relay RAZER to again become energized by its circuitpreviously traced. With relay RAZER again encrgized, while relay ZRDR isdeenergized, a circuit will be completed for lighting yellow lamp Y ofsignal RA2, this circuit passing from terminal 218, through the frontpoint of contact 8 of relay RAZER, back point of contact 9 of relayZRDR, and lamp Y of signal RAZ to terminal 2N.

When the first eastbound train enters section T, relay STR will becomedeenergized, causing relay -RER to become deenergized, and in turncausing lamp G or lamp Y of signal R4 to be extinguished, and lamp R ofthis signal to again be lighted. Contact 75 of relay STR will now beopen in the circuit for the BPR and FR relays. The pickup circuit tracedfor relay tEFP will be opened at contact 32 of relay STR, but relay 4EFPwill remain energized by its stick circuit previously traced. With relay4RER again deenergized, winding m of trans- 12 former 4LT will besupplied with current coded at the frequency of 75 times per minute, aspreviously described.

When the first eastbound train leaves section BT, Winding (1 oftransformer 3RT will again be energized by current coded at thefrequency of 75 times per minute, causing relay SRTR to in turn becomeenergized by current coded at this frequency, so that transformer 3T andrelay 3RHR will also be energized, but relay SRDR will not becomeenergized. Red lamp R of signal R3 will now be extinguished because ofthe opening of contact 14. of relay 3RHR at its back point, and theyellow lamp Y of this signal will again become lighted by the circuitpreviously traced.

When both eastbound trains have proceeded beyond signal LA l, and haveleft section 5T, a circuit will be completed, for energizing the BPRrelays, which is the same as the circuit previously traced forenergizing the BPR and the FR relays except that it includes contacts65, and 73 of relays ZBPR, 3BPR and dBPR, respectively. The 'BPR relays,upon becoming energized, will open their back contacts, so that relaysZFR, 31 R and 4FR will again become energized by the circuit previouslytraced for the BPR and FR relays. All parts of the apparatus will thenagain be in the condition shown in the drawings.

I shall next assume that a Westbound train is to move over the stretchof track shown in the drawings. A leverman will therefore move lever FVto its 1' position, causing relay FSR to become energized by current ofreverse polarity passing from terminal 2B, through contact 28 of leverFV, winding of relay FSR, and contact 29 of lever FV to terminal 2N.Contacts 62 and 76 of re lay FS'R will therefore be moved to the reverseposition. While these contacts are moving from the normal to the reverseposition, the BPR and FR relays will become de-. energized, and whencontacts 62 and 76 of relay FSR reach the reverse position, a circuitwill be completed, for energizing the BPR relays by current of reversepolarity, which is otherwise the same as the circuit previouslydescribed for energizing the .B PR relays through the back contacts ofthese relays. As soon as the BPR relays open their back contacts, therelays FR will also become energized by current of reverse polarity.

Each of the relays ZFR, SFR and 41 R, upon becoming energized by currentof reverse polarity, will move its polar contacts to the reverseposition, thereby deenergiz ing the EFF relays. Release of relays 3EFPand 4EFP interrupts the circuits supplying coded energy to the trackcircuits of sections AT and BT, respectively. As a result, relays ZRHR,ZRDR, and ERHR are deenergized and release. The traffic control circuitis therefore interrupted at contact 66 of relay ZRl-IR, contact 68 ofrelay SRHR, and contact 71 of relay iEFP. Contacts of relays ZFR, 31 R,and 4FR, however, remain in their reverse position.

A pickup circuit is now complete for energizing relay ZWFP, this circuitpassing from terminal 2B, through contact 58 of relay 2FR closed in thereverse position, contacts 83 and 84 of relays 2A8 and 1TR,respectively, contact 85 of relay ZEFP, and the Winding of relay ZWFP toterminal 2N. Relay ZWFP, upon becoming energized by its pickup circuit,will complete its stick circuit, which is the same as the pickup circuitjust traced except that it includes contact 36 of relay ZWFP instead ofcontacts 83 and 84 of relays 2A3 and lTR, respectively.

With relay ZWFP energized, winding m of transformer ZRT will beenergized by current coded at the frequency of times per minute suppliedto a circuit passing from terminal BX, through contact 87 of codetransmitting device 75CT, front point of contact 54 of relay ZWFP,winding m of transformer ZRT, and the front point of contact 55 of relayZWFP to terminal NX. Winding d of transformer 3LT will therefore now beenergized by A circuit will now be completed for energizing relay 3LTRfrom winding m of transformer 3LT, this circuit including winding m oftransformer 3LT, back point of contact 49 of relay 3EFP, rectifier 3L1,winding of relay 3LTR, and the back point of contact 48 of relay 3EFP.Relay 3LTR will therefore now be periodically energized at a frequencyof 75 times per minute, causing contact 88 of relay SLTR to be closed atits front and back points alternately.

Each time when contact 88 of relay 3LTR becomes closed at its backpoint, a circuit will be completed for charging an energy storingdevice, designated by the reference character e, this circuit passingfrom terminal 313, through the back point of contact 88 of relay 3LTR,energy storing device e, and a resistor t to terminal 3N. Each time whencontact 88 of relay 3LTR becomes closed at its front point, the energystoring device e will discharge through the winding of relay 3LHR, by acircuit passing from device e, through the front point of contact 88 ofrelay 3LTR, winding of relay 3LHR, and resistor t back to device e.Relay 3LHR is made slow releasing by asymmetric unit i5 connected inmultiple with its control winding, and therefore its front contacts 52,69 and 89 will remain closed while contact 88 of relay 3LTR is beingclosed alternately at its front and back points.

A pickup circuit will now be completed for relay 3WFP, passing fromterminal 3B, through contact 44 of relay SFR closed in the reverseposition, contact 89 of relay SLHR, contact 91 of relay SEFP, and thewinding of relay SWFP to terminal 3N. Relay 3WFP, upon becomingenergized, will complete its stick circuit, which is the same as thepickup circuit just traced except that it includes contact 94) of relaySWFP instead of contact 89 of relay 3LHR.

A circuit will now be completed for energizing winding m of transformerSRT by current coded at the frequency of 180 times per minute, thiscircuit passing from terminal BX, through the front point of contact 40of relay 3WFP, winding m of transformer 3RT, front point of contact 41of relay SWFP, contact 50 of code transmitting device 18OCT, front pointof contact 52 of relay 3LHR, and the back point of contact 53 of relay3RHR to terminal NX. Current coded at the frequency of 180 times perminute will therefore now be supplied from winding d of transformer 3RTover the rails of section BT, to winding d of transformer 4LT.

Relay 4LTR will now be energized by current coded at the frequency of180 times per minute in a circuit which includes winding m oftransformer 4LT, back point of contact 39 of relay 4EFP, rectifier 4LI,winding of relay 4LTR, and the back point of contact 38 of relay 4EFP.Transformer 4T and relays 4LHR and 4LDR will therefore now be energizedthrough contacts 92 and 93 of relay 4LTR while being repeatedly closedat their front and back points alternately at the frequency of 180 timesper minute. When relay 4LHR picks up, the traflic control circuit isagain completed, the previously described open contacts 66, 68, and 71being by-passed, respectively, by contact 67 of relay ZWFP, contact 69of relay 3LHR, and contact 72 of relay 4LHR. The BPR relays again pickup to open back contacts, and the FR relays are then reenergized bycurrent of reverse polarity.

With relay 4LHR energized, a pickup circuit will be completed for relay4WFP, this circuit passing from terminal 413, through contact 30 ofrelay 4FR closed in the reverse position, contact 94 of relay 4LHR,contact 96 of relay 4EFP, and the winding of relay 4WFP to terminal 4N.Relay 4WFP, upon becoming energized by its pickup circuit, will completeits stick circuit, which is the same as the pickup circuit just tracedexcept that it includes contact 95 of relay 4WFP instead of contact 94of relay 4LHR.

A leverman can now control signal LA4 to display a green or clearproceed indication for a westbound traffic movement, similarly to themanner previously described for controlling lamp G of signal RA2 todisplay a green or proceed indication for an eastbound train.

I shall now assume that all parts of the apparatus are again in thecondition shown in the drawings. I shall assume further that a levermancontrols signal RA2 to display the green or clear proceed indication foran eastbound train, and that the eastbound train has moved past signalRA2 over track section IT and onto section AT. I shall assume still:further that, as before applicant made his invention, there are noneutral line relays BPR in series with the FR relays.

I shall also assume that, while an eastbound train is on section AT, asurge of current of foreign reverse polarity is induced, in any mannerpreviously described, and flows through relay BPR, causing the contactsto relay 3FR to move to the reverse position. With contact 44 of relay3FR moved to the reverse position, relay 3EFP will be deenergized. Withrelay 3EFP deenergized, the winding of relay 3LTR will be connected withwinding m of transformer 3LT through the back points of contacts 48 and49 of relay SEFP.

Now, when the eastbound train leaves section AT, relay ZRTR at the westend of section AT cannot become energized, because relay 3LTR isconnected across the rails at the east end of section AT. Therefore,relay 2RTR, and also relay 3LTR, will remain deenergized and so, whenthe eastbound train has completed its movement over the stretch of trackshown in the drawings and has left track section ET, the circuit for theFR relays will be open at contact 66 of relay ZRHR as well as at contact67 of relay ZWFP. In order to restore the apparatus to the conditionshown in the drawings, it will then be neces sary for a maintainer orother authorized employee to go to the location of signal R3 andmanually effect restoration of the contacts of relay 3FR to the normalposition in agreement with the contacts of relays 2FR and 4FR.

From the foregoing description, it follows that my invention protectsagainst misplacement of the polar con-' tacts of polar control relays ina control circuit which may include only one polar control relay orwhich'may include a plurality of polar control relays connected inseries, by a surge of current induced by a foreign source while thecircuit is deenergized, such as in traific locking apparatus, or in acircuit which is normally deenergized or becomes deenergizedaccidentally, by providing a neutral relay for each polar control relay,with a shunt path completed around the control winding of the corresponding polar control relay through a back contact of the neutral relaywhile the control circuit is deenergized.

Although I have herein shown and described only one form of apparatusembodying my invention, it is understood that various changes andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In railway trafiic controlling apparatus for a stretch of railwaytrack which is divided into a plurality of sections and is provided witha plurality of traflic governing devices spaced consecutively along saidstretch for governing trafiic movements in a first direction and in theopposite or second direction, embodying a plurality of polar controlrelays connected in series in a traflic control circuit arrangement,each of said relays having polar contacts which when the correspondingrelay becomes deenergized remain closed in a normal or a reverseposition to which they were last operated in response to current ofnormal or reverse polarity respectively, in which energization of saidtraffic control circuit arrangement including said polar control relaysconnected in series by current of normal and reverse polarities ismanually controllable from only one control station, in which two trackcircuits are provided for each of given sections one for each directionof traffic movements, in

which energization of each of the track circuits for a given directionof traffic movements is controlled by a contact of a corresponding polarcontrol relay when closed in the normal position and energization ofeach of the track circuits for the opposite direction of trafiicmovements is controlled by a contact of a corresponding polar controlrelay when closed in the reverse position, in which said trafiic controlcircuit arrangement includes contact means controlled by said trackcircuits and closed only while said track circuits are energized, and inwhich each of said trafiic governing devices is controlled by acorresponding one of said track circuits, the combination comprising, aplurality of neutral line relays one adjacent each of said polar controlrelays connected in series with said polar control relays and said trackcircuit controlled contact means in said trafiic control circuitarrangement, and a branch circuit path connected in shunting relationaround the control winding of each of said polar control relays in saidtrafiic control circuit arrangement to prevent operation of said polarcontrol relays to their opposite position by transient voltagesoccurring while said traffic control circuit is open, each of saidbranch circuit paths including a back contact of the correspondingneutral line relay.

2, In railway traflic controlling apparatus for a stretch of railwaytrack which is divided into a plurality of sections and is provided witha plurality of trafllc governing devices spaced along said stretch forgoverning traflic movements in a first direction and in the opposite orsecond direction, embodying a plurality of polar control relaysconnected in series in a traffic control circuit arrangement, each ofsaid relays having polar contacts which when the corresponding relaybecomes deenergized remain closed in a normal or a reverse position towhich they were last operated in response to current of normal orreverse polarity respectively, in which enegization of said trafiiccontrol circuit arrangement including said polar control relaysconnected in series by current of normal and reverse polarities ismanually controllable, in which two track circuits are provided for eachof given sections one for each direction of traffic movements, in whichenergization of each of the track circuits for a given direction oftrafiic movements is controlled by a contact of a corresponding polarcontrol relay when closed in the normal position and energization ofeach of the track circuits for the opposite direction of trafficmovements is controlled by a contact of a corresponding polar controlrelay when closed in the reverse position, in which said trafiic controlcircuit arrangement includes contact means controlled by said trackcircuits and closed only while said track circuits are energized, and inwhich each of said trafiic governing devices is controlled by acorresponding one of said track circuits, the combination comprising, aplurality of neutral line relays one for each of said polar controlrelays connected in series with said polar control relays and said trackcircuit controlled contact means in said trafiic control circuitarrangement, and a branch circuit path connected in shunting relationaround the control winding of each or" said polar control relays in saidtrafi'ic control circuit arrangement to prevent reversal of the contactsof said polar control relays by current surges induced in portions ofsaid traffic control circuit, each of said branch circuit pathsincluding a back contact of the corresponding neutral line relay.

3. In railway traffic controlling apparatus for a stretch of railwaytrack which is divided into a plurality of sections and is provided witha plurality of signals spaced consecutively along said stretch forgoverning traffic movements in a first direction and in the opposite orsecond direction, embodying a plurality of polar control relaysconnected in series in a trafiic control circuit arrangement, each ofsaid relays having polar contacts which when the corresponding relaybecomes deenergized remain closed in a normal or a reverse position towhich they were last operated in response to current of normal orreverse polarity respectively, in which energization of said trafiiccontrol circuit arrangement including said polar control relaysconnected in series by current of normal and reverse polarities ismanually controllable, in which two track circuits are provided for eachof given sections one for each direction of traflic movements, in whichenergization of each of the track circuits for a given direction oftrafiic movements is controlled by a contact of a corresponding polarcontrol relay when closed in the normal position and energization ofeach of the track circuits for the opposite direction of traflicmovements is controlled by a contact of a corresponding polar controlrelay when closed in the reverse position, in which one of said signalsadjacent each end of said stretch for governing trafiic movements ontosaid stretch is in part manually controllable, in which said tralficcontrol circuit arrange ment includes contact means controlled by saidtrack circuits and closed only while said track circuits are energizedand also includes contact means normally closed but controlled to becomeopened when either of said signals adjacent opposite ends of saidstretch is manually controlled for displaying a proceed indication, andin which each of said signals is also controlled by a corresponding oneof said track circuits, the combination comprising, a plurality ofneutral line relays one for each of said polar control relays connectedin series with said polar control relays and said contact means, and abranch circuit path connected in shunting relation around the controlWinding of each of said polar control relays in said traflic controlcircuit arrangement to prevent operation of said polar control relays totheir opposite positions by induced surges of foreign current occurringwhile such traffic control circuit is deenergized, each of said branchcircuit paths including a back contact of the corresponding neutral linerelay.

4. In railway trafiic controlling apparatus for a stretch of railwaytrack which is divided into a plurality of sections, embodying aplurality of polar control relays connected in series in a trafiiccontrol circuit arrangement, each of said relays having polar contactswhich when the corresponding relay becomes deenergized remain closed ina normal or a reverse position to which they were last operated inresponse to current of normal or reverse polarity respectively, in whichenergization of said traflic control circuit arrangement including saidpolar control relays connected in series by current of normal andreverse polarities is manually controllable, in which two track circuitsare provided for each of given sections one for each direction oftrafiic movements, in which energization of each of the track circuitsfor a given direction of tratfic movements is controlled by a contact ofa corresponding polar control relay when closed in the normal positionand energization of each of the track circuits for the oppositedirection of trafiic movements is controlled by a contact of acorresponding polar control relay when closed in the reverse position,in which said tratfic control circuit arrangement includes contact meanscontrolled by said track circuits and closed only While said trackcircuits are energized, and in which said track circuits control traflicgoverning means, the combination comprising, a plurality of neutral linerelays one for each of said polar control relays connected in serieswith said polar control relays and said contact means, and a branchcircuit path connected in shunting relation around the control windingof each of said polar control relays in said trafi'ic control circuitarrangement, each of said branch circuit paths including a back contactof the corresponding neutral line relay, whereby the operation of saidpolar control relays to an opposite position by induced surges offoreign current is prevented.

5. In railway trafiic controlling apparatus for a stretch of railwaytrack which is divided into a plurality of sections, embodying aplurality of polar control relays in which energization of said trafiiccontrol circuit arrangement including said polar control relaysconnected in series by current of normal and reverse polarities ismanually controllable, in which two track circuits are provided for eachof given sections one for each direction of traffic movements, in whichenergization of each of said track circuits for a given direction oftraffic movements is controlled by a contact of a corresponding polarcontrol relay when closed in the normal position and energization ofeach of said track circuits for the opposite direction of traflicmovements is controlled by a contact of a corresponding polar controlrelay when closed in the reverse position, in which said traffic controlcircuit arrangement includes contact means controlled by a track circuitfor each of said sections and closed only while. the corresponding trackcircuit is energized, and in which said track circuits control trafficgoverning means, the combination comprising, a plurality of neutral linerelays one for each of said polar control relays connected in serieswith said polar control relays and said contact means, and a branchcircuit path connected in shunting relation around the control windingof each of said polar control relays in said traific control circuitarrangement, each of said branch circuit paths including a contactcontrolled by the corresponding neutral line relay and closed while thecorresponding neutral line relay is deenergized, whereby the operationof said polar control relays to an opposite position by induced surgesof foreign current is prevented.

6. In combination, a stretch of railway track divided into sections,traffic governing means for governing traffic movements in a givendirection and also in the opposite direction over said stretch ofrailway track, a plurality of polar control relays, a plurality ofneutral line relays one for each of said polar control relays, trafiicresponsive means for each of said track sections including two trackcircuits for each of given track sections one for each direction oftraflic movements, trafiic responsive contact means for each of saidsections controlled by said trafiic responsive means and normally closedbut becoming opened when the corresponding track section becomesoccupied by a train, a trafiic control circuit arrangement includingsaid polar control relays and said neutral line relays and also saidtraflic responsive contact means all in series, manually controllablemeans for effecting energization of said traflic control circuitarrangement by current of normal and reverse polarities, meanscontrolled by normal and reverse polar contacts of said polar controlrelays for setting up the track circuits for said given track sectionsfor traffic movements in a normal or a reverse direction respectively,means controlled by said traffic responsive means for controlling saidtraffic governing means for trafiic movements in said normal or saidreverse direction according as said normal or reverse polar contactsrespectively of said polar control relays are closed, and a branchcircuit path connected in shunting relation around the control Windingof each of said polar control relays in said traffic control circuitarrangement to prevent operation of said polar control relays to theiropposite positions by induced surges of foreign current occurring whilesuch traffic control circuit is deenergized, each of said branch circuitpaths including a contact controlled by the corresponding neutral linerelay and closed while the corresponding neutral line relay isdeenergized.

7. In combination, a stretch of railway track, trafiic governing meansfor governing traflic movements in a given direction and also in theopposite direction over said stretch of railway track, a plurality ofpolar control relays, a plurality of neutral line relays one for each ofsaid polar control relays, traflic responsive contact means for saidstretch of track normally closed but becoming opened in response to atrafiic movement over said stretch of track, a traflic control circuitarrangement including said polar control relays and said neutral linerelays and also said trafiic responsive contact means all in series,manually controllable means for energizing said traffic control circuitarrangement by current of normal and reverse polarities,

a plurality of branch circuit paths one for each of said polar controlrelays each connected in shunting relation around the control winding ofthe corresponding polar control relay to prevent reversal of thecontacts of said polar control relays by induced current surges whilesaid trafiic control circuit is deenergized, each of said branch circuitpaths including a contact controlled by the corresponding neutral linerelay to be closed While the corresponding neutral line relay isdeenergized, and means controlled by normal and reverse polar contactsof said polar control relays for controlling said traffic governingmeans for governing trafiic movements in a first direction or in theopposite direction respectively over said stretch of track.

8. In combination, a plurality of electrical devices, a plurality ofpolar control relays, each of said relays having polar contacts whichwhen the corresponding relay becomes deenergized will remain closed in anormal or a reverse position to which they were last operated inresponse to energization of the corresponding relay by current of normalor reverse polarity respectively, a plurality of neutral line relays onefor each of said polar control relays, a control circuit including saidpolar control relays and said neutral line relays connected in series,manually controllable means for energizing said control circuit bycurrent of normal and reverse polarities, a plurality of branch circuitpaths one for each of said polar control relays each connected inshunting relation around the control winding of the corresponding polarcontrol relay to prevent reversal of the contacts of said polar controlrelays by induced current surges while said control circuit isdeenergized, each of said branch circuit paths including a contactcontrolled by the corresponding neutral line relay to be closed when thecorresponding neutral line relay is deenergized, and means controlled bysaid polar contacts of said polar control relays in the normal andreverse positions for selectively controlling said electrical devices ina first or a second given manner respectively.

9. In combination, electrical apparatus, a polar control relay having apolar contact which when the relay becomes deenergized will remainclosed in a normal or a reverse position to which it was last operatedin response to energization of the relay by current of normal or reversepolarity respectively, a neutral line relay, a control circuit includingsaid polar control relay and said neutral line relay connected inseries, control means for effecting energization of said control circuitby current of normal and reverse polarities, a branch circuit pathconnected in shunting relation around the control winding of said polarcontrol relay in said control circuit, said branch circuit pathincluding a contact controlled by said neutral line relay to be closedwhen said neutral line relay is deenergized, said branch circuit pathbeing efiective to prevent the operation of said polar control relay bytransient voltages while said control circuit is deenergized, and meanscontrolled by said polar contact in its normal and reverse positions forselectively controlling said electrical apparatus in a first or a secondgiven manner respectively.

10. In combination, electrical apparatus, a polar control relay having apolar contact which when the relay becomes deenergized will remainclosed in a normal or a reverse position to which it was last operatedin response to energization of the relay by current of normal or reversepolarity respectively, a neutral line relay, a control circuit includingsaid polar control relay and said neutral line relay, control means forelfecting energization of said control circuit by current of normal andreverse polarities, a short-circuit branch path connected in shuntingrelation around the control winding of said polar control relay in saidcontrol circuit, said branch path including a contact controlled by saidneutral line relay to be closed when said neutral line relay isdeenergized, said branch path being effective to prevent the operationof said polar control relay gization of the relay by current of normalor reverse' polarity respectively, a neutral line relay, a controlcircuit including said polar control relay and said neutral line relay,control means for eifecting energization of said control circuit bycurrent of normal and reverse polarities, a short-circuit branch pathconnected in shunting relation around the control winding of said polarcontrolrelay in said control -circuit,"said branch path including acontact controlled by said neutral line relay to be closedwhen saidneutral line relay and said polar controlrelay'are deenergized, saidbranch path being effective to'prevent' the operation of said polarcontrol relay by transient voltages While said relays are deenergized,and means controlled by said polar contactinits normal and reversepositions for selectively controlling said electrical apparatus ina'first or a second given manner respectively.

12. Incombination, electrical apparatus, a polarcontrol relayhaving apolar contact whichwhen the'relay becomes deenergized will remain closedin a normal or a reverse position to which it was last operated inresponse to energizationof the relay by current ofnormal or reversepolarity respectively, a neutral line relay, a control circuit includingsaid polar-control relay and-said neutral line relay, control meansfor"effecting energization offsaid control circuit by current of normaland reverse polarities,

a'short-cir'cuitbranch path connected in shunting relationaround thecontrol winding of said polar control relay in said control circuit,said branch path including a contact controlled by'said neutral linerelay to be closed when said polar control relay is deenergized, saidbranch path being effective to prevent the operation of said polarcontrol relay by transient voltages while said polar control relay isdeenergized, and means controlled by said polar contact in its normaland reverse positions for selectively controlling said electricalapparatus in a' first or a second given manner respectively.

13. In combination, a stretch of railway track, trafiic governing meansfor governing traffic movements in a given direction and also inthe'opposite direction .over

said stretch of railway track, a plurality of polar control manuallycontrollable means for energizing. said ,traflic control "circuitarrangement by current of normal and reverse polarities, a plurality ofshort-circuit branch paths one for each of said polar control relayseach connected in shunting relation around the control winding ofthecorresponding polar control relay, each of said branch paths including acontact controlled by the corresponding neutral line relay to be closedWhile the corresponding neutral line relay is'deenergized, said branchpaths being effective to prevent reversal of the contacts of said polarcontrol relays by induced current surges while said traffic controlcircuit is deenergized, and means controlled by normal and reverse polarcontacts of said polar control relays for controlling said traificgoverning means for'governing trafiic movements in a first direction orin the opposite direction respectively over said stretch of track.

14. In combination, a stretch of railway track, traflic governing meansfortgoverning trafiic movements in a given direction and also in theopposite direction over said stretch of railway track, a plurality ofpolar control relays, a plurality of neutral line relays one for each ofsaid polar control relays, traffic responsive contact means for saidstretch of track normally closed but becoming opened in response to. atrafiic .movement over said stretch of track, a trafiic control circuitarrangement including saidpolar control relays and said neutral linerelays andalso said trafiic responsive contact means all in series,manually controllable means for energizing said traffic control circuitarrangement by current of normal and reverse polarities, a plurality ofshort-circuit branch paths one foreach of said polar control relays eachconnected in shunting relation around the control Winding of thecorresponding'polar control relay, each of said branch'paths including acontact controlled by the corresponding neutral line relay to be closedwhile the corresponding polar control relay is deenergized, each saidbranch path being effective to prevent operation of the correspondingpolar control relay by transient voltages while said corresponding polarrelayis deenergized, and means controlled by normal and reverse polarcontacts of said polar control relays for controlling said traflicgoverning means for governing traffic movements in a first direction orin the opposite direction respectively oversaid stretch of track.

References Cited in the tfile of this patent UNITED STATES PATENTS1,248,942 *Sprague Dec. 4, 1917 1,322,148 Sprague Nov. 18, 19192,271,510 Allen Feb. 3, 1942 2,343 ,001 Cohen Feb. 29, 1944 2,366,776'Fail'or Jan. 9, 1945 2,618,740 Grosjean 'Nov. 18, 1952 2,697,778 Hursh,Dec. 21, 1954

